Striking doctors and a host of other workers have joined thousands of anti-government protesters in Egypt.
Medics wearing white coats streamed into Cairo's Tahrir Square alongside demonstrators who continue to call for President Hosni Mubarak to resign.
A key Cairo hospital was reported to have been closed by strike action as an estimated 3,000 staff walked out.
The renewed protests come after Egypt's foreign minister criticised US calls for Egypt to lift its emergency law.
Rebuffing Washington's calls to speed up the pace of political reform, Ahmed Aboul Gheit said Washington should not "impose" its will on "a great country".
Many thousands of Egyptians have been protesting since 25 January, calling for President Hosni Mubarak to step down.
Mr Mubarak has said he intends to step down after presidential elections, due to be held in September.
Protests in Cairo have now spread to Egypt's parliament, with violence and reports of strikes in other cities.
Bus drivers, lawyers and textile workers were reported to have joined the doctors on strike on Thursday, with unions reporting walkouts and protests across the country.
In the centre of Cairo, medics streamed out of the Qasr al-Aini teaching hospital heading towards Tahrir Square.
"This is not about our wages, this is about holding those in power accountable and about getting our freedoms," Soha Mohammed, who works at the hospital, told the AFP news agency.
An organised protest camp now exists in the square, which has been the focal point for demonstrations that are now in their 17th day.
The BBC's Jon Leyne, in the square, reported that large numbers of protesters had turned out on Thursday, despite poor weather and suggestions that protest leaders were hoping to concentrate on mustering support for a major rally on Friday.
"We demand a trial of Mubarak and his regime; we are protesting [against] corruption," Mohammed Zarie, marching with a column of lawyers, told the Associated Press.
Away from Tahrir Square, there were reports of union-organised strikes and walkouts elsewhere in Egypt.
Staff at a textile factory reported to be Egypt's largest walked out and locked the gates, AFP reported. Bus stations around Cairo were closed. One union official spoke of a "definite escalation" among workers since the Tahrir Square protests began.
Egypt's Vice-President Omar Suleiman has warned protesters against strikes and acts of civil disobedience, saying there could be "chaos" if the military and security forces end up taking action against demonstrators.
Negotiations between the government and opposition groups have made little progress, with protesters disillusioned at the plans for reform put forward by Mr Mubarak's government.
Google executive Wael Ghonim, who has become a figurehead for many in the protest movement after being released from 12 days of detention, said on Thursday he had no plans to stay involved in politics longer than necessary.
Instead he described himself as "honoured" to be involved in negotiations with the government.
"I promise every Egyptian that I will go back to my normal life and not be involved in any politics once Egyptians fulfil their dreams," Mr Ghonim tweeted.
'Genie out of the bottle'
In his interview with US network PBS, Mr Aboul Gheit said Egypt was enduring an "upheaval", and was sharply critical of US statements on Egypt, including Vice-President Joe Biden.
Explicit calls from Mr Biden for "prompt, immediate" action from Egypt were tantamount to "imposing your will" on a long-time ally of the US, Mr Aboul Gheit said.
On the issue of Egypt's emergency law, in place for four decades, Mr Aboul Gheit described himself as "amazed" by Mr Biden's reported comments for it to be lifted.
Jailbreaks amid the recent street protests meant that 17,000 prisoners are now loose on Egypt's streets, the foreign minister said.
"How can you ask me to disband the... emergency law while I'm in difficulty? Give me time."
Despite Mr Aboul Gheit's words, Washington once again reiterated its call for rapid and meaningful change in Egypt.
"I think it is clear that what the government has thus far put forward has yet to meet a minimum threshold for the people of Egypt," White House spokesman Robert Gibbs said.
"And I think, unless or until that process takes hold, I think you're going to see the continued pictures that all of us are watching out of Cairo and of other cities throughout Egypt.
"If there's some notion on the government side that you can put the genie back in this bottle, I think that's gone a long time ago," he added.